FIG. 1 shows a cable fitting 8 (sometimes referred to as a conduit fitting) which is comprised of a first opening 25, a second opening 26, cover plate retaining holes 21-24 and an interior volume 27 that is disposed between the first opening 25 and the second opening 26. The cable fitting is designed such that a cable can occupy the interior volume 27. The cable fitting also includes cover plate retaining holes 21-24 that permit the mounting of a cover plate to the cover plate plane of the cable fitting 8 once a cable has been installed into the fitting.
FIG. 2 is a diagram describing how a cable 20 is moved through two cable fittings, a first cable fitting 17 and a second cable fitting 18. The cable 20 in this diagram is a three conductor 500 MCM electrical cable which is approximately three inches in diameter, heavy and difficult to maneuver. The cable 20 will be pulled from the cable tray 13, through first cable fitting 17 and then through second cable fitting 18. Conduit 9 is protective tubing which the cable 20 is also pulled through and is located between the cable tray 13 and then connected to the first opening 25 of first cable fitting 17, between the second opening 26 of first cable fitting 17 and first opening of second cable fitting 18. Additional conduit is also attached to the second opening 26 of second cable fitting 18 and extends beyond the second cable fitting 18. In this diagram the first cable fitting 17 is separated from second cable fitting 18 by approximately four-hundred feet. Installation of the cable 20 through first cable fitting 17 and out of second cable fitting 18 requires two cable pulls. The first pull involves pulling enough cable 20 to reach the second cable fitting 18, over four-hundred feet in length, from cable tray 13, through conduit 9, and through the first opening 25 of first cable fitting 17. Three pulling wheels with anchor plates 10-12, a pulling wheel 15 and a tugging machine 16 are used to pull the cable 20 through first cable fitting 17 in the direction of the first pull. Pulling wheel 15 is attached to the bumper of a stationary truck. The pulling wheels with anchor plates 10-12 are anchored into concrete. Tugging machine 16 pulls the cable 20 from the first opening of first cable fitting 17 in the direction of the first pull around pulling wheel 10, then around pulling wheel 15 to pulling wheel 11 and then around pulling wheel 12.
Once the first pull has been completed, the entire length of cable is available to be hand fed back into the second opening 26 of the first cable fitting 17. In order to complete the first pull, anchor locations are necessary for the three pulling wheels with anchor plates 10-12 and pulling wheel 15 anchored to the truck bumper. The entire length of cable is exposed during the first pull and may have to be laid adjacent a roadway and marked with warning tape or cones. Additionally, damage from contact with automobile traffic is possible when the cable is exposed in this manner. To arrange the pulling wheels with anchor plates 10-12, the tugging machine 16, pulling wheel 15 and to handle the heavy cable and feed it back into the first cable fitting 17 requires, approximately, a team of eight persons working one eight hour day.
Once the first pull is completed, a second pull is necessary to pull the cable 20 through the second opening 26 of the first cable fitting 17 through conduit and through the first opening of cable fitting 18. The cable fitting is pulled in the direction of the second pull through the first opening in the second cable fitting 18 by pulling motor 19.
Because pulling the cable through fittings as described is labor intensive, of significant duration and exposes the electrically conducting cable 20 to hazards, another method is desirable to reduce the amount of labor and time required to install cable through cable fittings and one that reduces the possibility of damage to the cable.